Subject: Re: power management and related concerns
To: Garrett D'Amore <>
From: Jason Thorpe <>
List: tech-kern
Date: 07/05/2006 11:24:57
On Jun 30, 2006, at 5:28 PM, Garrett D'Amore wrote:

> 1) there doesn't seem a clear way to indicate powerfail for a low
> battery condition in sysmon.  Should I just be sending init some  
> signal?

You should add this capability to sysmon :-)  powerd(8) can then  
handle the message.

> 3) Currently it isn't clear whether you should be registering with  
> APM,
> sysmon, or something else for things like battery status, etc.  It  
> would
> be really, really good if drivers didn't have to do _both_ of these
> things.  Can we maybe have a sysmon APM compatibility layer?  (I guess
> there are some userland apps that "know" about APM.  Bletch.)

BACKWARDS!  sysmon is where things should be going.  The whole idea  
is that sysmon is a generic system that has back-ends for APM, ACPI,  
etc.  Right now, sysmon is just a skeleton, but it has some pieces  
there that e.g. ACPI is using now.

> 4) We need some userland tools to talk to sysmon in base, I think.
> (E.g. to query batteries, etc.)
> 5) In many respects, sysmon looks like a good start.  I've coded a  
> quick
> power management driver for the Ultrabook IIi (okay, it was mostly a
> port from Solaris), and it basically works for things like lid switch,
> AC power cord un/plug, and power button.

Yah, that was the whole idea :-)

-- thorpej